1. Field of the Invention
The present invention is directed to a therapy apparatus for locating and treating a zone in the body of a living subject with acoustic waves.
2. Description of the Prior Art
Devices of the type generally described above are known which include an electro-acoustic transducer that can be optionally operated in the therapy mode or the locating mode, which resonates in the therapy mode for producing therapeutic, acoustic waves focused onto a zone of action and resonates in the locating mode for producing diagnostic, acoustic waves. In the locating mode the transducer also receives parts of the diagnostic acoustic waves reflected in the body of the subject and converts them into electrical signals. Evaluation electronics, supplied with the received signals, provides image information about the zone to be treated.
Such therapy systems are employed, for example, for treating pathological tissue changes. The pathological tissue is thereby heated by focused ultrasound waves emitted as therapeutic acoustic waves. Insofar as the resulting tissue temperatures lie below 45.degree. C., the cell metabolism is disturbed with the consequence that a retardation of the growth, or even an abatement, of the pathological tissue occurs in the case of tumors. This type of treatment is known as local hyperthermia. When temperatures beyond 45.degree. C. are reached, the cell protein coagulates, with the consequence of necrotization of the tissue. This latter type of treatment is referred to as thermotherapy. The therapeutic acoustic waves are emitted as continuous sound that is always interrupted when the emission of diagnostic acoustic waves ensues.
A therapy system suitable for local hyperthermia or, for thermotherapy wherein separate transducers are provided for locating and therapy is disclosed in U.S. Pat. No. 5,036,855. This apparatus has an applicator head that accepts the transducers for locating and therapy and which can be introduced into body cavities.
Therapy devices of the type initially cited can also be employed in the treatment of stone maladies (lithotripsy) and bone conditions (osteorestoration). In these cases, the therapeutic acoustic waves are emitted, for example, in the form of shock waves.
Devices of the type initially cited are disclosed, for example, in U.S. Pat. No. 4,526,168 and by European Application 0 194 897. In both instances, it is not possible under all circumstances to identify the position of the zone to be respectively treated on the basis of the available image information with such precision that this zone can be positioned exactly in the effective region of the therapeutic acoustic waves.